SU1764750A1 - Rings making method - Google Patents

Description

one

4922559/27

02.01.91

09/30/92. Bul №36

Institute of Ferrous Metallurgy and Taganrog Metallurgical Plant (72) V.I. Kheifets, L.A. Levitsky, O.G.Baranets, E.F.Omilaev, V.V., Kuchin, N.V.Chvilev and V. M.Ozimin

(56) G. Fieregge. Lay-up of forge shops with regard to the production of blanks for rolling rings. Ferrous metals, No. 10, 1971, p. 29

(54) METHOD OF MANUFACTURING RING PRODUCTS

(57) Use: in the manufacture of solid-rolled ring products for machine T

construction, chemical engineering, aircraft manufacturing. Essence: the initial billet is heated, precipitated and dispersed by a punch. Then a hollow ring billet is molded, forming its inner surface in the form of a torus surface with a radius determined from the above dependence. After forming, the billet is deformed on a ring rolling mill in a closed caliber to the size of the finished product. The products obtained by this method do not have burrs on the inner surface of the workpiece. 1 il.

The invention relates to the processing of metals by pressure and can be used in the manufacture of solid rolled ring products for mechanical engineering, chemical engineering, aircraft manufacturing, and the like.

Solid rolled ring products are manufactured on various production lines using a variety of press-forging equipment to prepare the workpiece before rolling on a ring rolling mill. Ring rolling mills of various designs can be used for rolling rings: radical rolling is carried out between two rolls in closed calibers, radial-axial rolling between two pairs of rolls (a pair of cylindrical rolls and a pair of tapered rolls).

A known method of manufacturing ring products, including heating the billet, its upset on the press, punching up with a punch followed by piercing the cage with the formation of a cylindrical central hole, then the billet is rolled out on a radial ring mill between two rolls of different diameters, of which the outer one is larger . Rolling is carried out in a closed caliber.

The disadvantage of this method is the low quality of the products due to the presence of burrs on the inner surface of the product. This is because the rolling of the ring blanks is carried out by deforming it only in the radial direction and in closed calibers, which causes the formation of the indicated defect.

The closest to the claimed technical essence and the achieved effect is a method of manufacturing ring products, including heating the billet, its slump, punching up, piercing, molding and subsequent rolling.

The disadvantage of this method of manufacturing ring products is low

cl

with

vj About 4 VJ SL 0

product quality due to the presence of burrs on the inner surface of the product and, consequently, an increase in labor intensity during the machining of ring blanks.

The aim of the invention is to improve the quality of the obtained ring products by eliminating the burrs on the inner surface of the ring products.

For this, in the known method of manufacturing ring products during the molding process, the inner surface is formed as part of a torus surface, the radius of which is determined from the dependence

„Г1М (Ј) g + (+1) 21-Г (1) а + (+ тП (д. + 4) а (т) г + (Д5- + т) г + Ч

where R is the radius of the torus surface;

h - the height of the workpiece for rolling;

L SBH - the amount of compression on the wall thickness from the inside;

d - the value of the field of permissible maximum deviations per internal diameter.

The radius of the part of the torus surface is determined based on the amount of reduction of the wall thickness on the inner side and half of the floor of permissible maximum deviations per inner diameter. This value will be equal to MB D5Vn + d II (figure 1). Therefore, a part of the torus surface on the plane is a part of the circumscribed circle of an isosceles triangle DAI.

The formula for the radius of the circumscribed circle is given by

R

4 cos (a / 2) cos (D / 2) cos (y / 2)

where P is the semi-perimeter of an isosceles LAVS triangle.

a, / 3, y-angles of an isosceles triangle AABC.

The semi-isometric triangle perimeter for this case is

p - g + 1sh2 + () g;

The cosine of the half angle "for an isosceles triangle L ABC is equal to the cosine of the angle a / 2 of the right-hand / n triangle D Navy (D VMA)

cos (a / 2) I MB I I VS I

D5vn + d / 2

(-) 2+ (D5vn + s) / 2) 2

5So as a triangle DAVAS is isosceles, THEN / .VAS / DIA (// / y). The expression for finding the cosine function of the half angle is

ten

cos

(P / 2) C | 1

+ cos D

15

From the AVMA right triangle:

cos /

JAM I I AB I

20

2 | ((D5vn + U2)

25

Thus, cos (ft / 2)

five

0

five

0

five

0

  1 Ih

| 2 4 | h / 2) 2+ (ASBH + d / 2) 2

After substituting all members, we find an expression for determining the radius of the torus surface, which is defined for each ring size and depends on the geometrical parameters of the ring article and the amount of rolling.

The height of the billet for rolling for radial-type mills is equal to the height of the finished ring product, which in turn is determined on the basis of the dimensions of the finishing part after machining, taking into account the allowances and permissible limit deviations on the geometrical parameters of the product. The amount of allowances and permissible maximum deviations is regulated by the relevant regulatory and technical documents (GOST, TU, etc.) and these values are determined for all types of ring products.

During rolling of an annular billet with a hole in the form of a torus on a radial mill in a closed caliber, compression occurs at the initial moment, E in the middle zone. As compression increases and, thus, as the diameter increases, the contact value of the inner surface of the rolled the annular billet with the inner shaft increases. Extreme points of the contact surface approaching

to the edges of the inner roll. In the final rolling period, the gauge is completely full. Burrs are not formed in this case.

The shape of the hole as part of a torus is adopted for reasons of obtaining high-quality annular products with an internal diameter, without sunsets, captivity, folds. The shape of the torus part contributes to the uniform flow of the metal and eliminates the influence of the resulting broadening, resulting in the above defects.

Figure 1 is a construction diagram for determining the radius of a circle; Fig. 2 shows the burr formation by internal diameter when rolling in a closed caliber; on fig.Z - the original billet; Figure 4 shows the upset preform; figure 5 - billet after distillation; FIG. 6 shows a blank; 7 is a molded billet; on Fig - finished ring product after rolling.

The drawings indicate: 1 — outer roll of a ring rolling mill, 2 — inner roll of a ring rolling mill, 3 — rolled ring blanks, Ho — height of the initial blank, D0 — diameter of the initial blank, H — height of the initial blank after draft, dn — diameter - sewing hole, h - height of the blank for rolling, da - inner diameter of the blank for rolling, hi - height of the finished ring product, D - outer diameter of the finished ring product, d - inner diameter of the finished ring product, R - radius of the torus surface ti.

The original billet (fig.Z) sizes H0 x Do, mass m is heated in a furnace to the temperature of deformation. Then, the heated billets are issued individually to the press-rolling line. On the press, the initial billet (fig.Z) is upset to the height H (figure 4). Then the upset preparation is subjected to distillation (FIG. 5) and piercing (FIG. 6) with a cylindrical punch (not shown in FIG. 5 and FIG. 6). Then, the resulting hollow annular billet is molded (Fig.7) to obtain a billet dimensions, height h, internal diameter ds. At this stage, the inner surface is formed as a part of the torus surface with radius R. The radius value is calculated in advance, based on the parameters of the finished annular product (Fig. 8) and the reduction value calculated by various known methods for wall thickness on the inside . The height of the ring blank for rolling is rolled equal to the height of the finished ring article h - hi.

Forming the inner surface of the hole as a part of the torus surface can be carried out on various forging and pressing equipment using a variety of deformation tools: on the hammer using curly heads; on the press using figured stamps.

After forming, the billet is deformed on a ring rolling mill in a closed caliber to the dimensions of the finished product D x d x hi.

Example. The original billet (fig.Z) with dimensions of D0 270 mm H0 216 mm and mass 97 kg m was heated in a ring furnace to a deformation temperature t 1260-1280 ° С. Then, the heated initial billets were individually fed to the press with a force of 800 ton-force (not shown in FIG. 4), where they were settled down by 20-25% to a height of H 162-172 mm. Then, the billet was distilled, followed by flashing the central hole with a cylindrical punch (not shown in FIGS. 5 and 6). As a result of these operations, a hollow billet with height H 162-172 mm and with a hole dn 180 mm was obtained. After that, the resulting hollow billet was subjected to molding on a horn hammer with an MUF of 6.6 tons

The hammer horn was previously made with a stream to form the inside surface of the hole. The hammer's horn brook had a curvature corresponding to the radius of the part of the torus surface calculated for the rolling billet,

The calculation was made as follows. The dimensions of the finished ring product, taking into account the maximum permissible deviations for the geometrical parameters, are equal to D x d x hi 600 ± 5 x 520 ± 5 x 150 ± 5 mm. The height of the billet for rolling h for a closed caliber is assumed to be equal to the height of the finished product hi 150 mm, the value of the field of permissible limit deviations per internal diameter according to the specifications and technical documentation is 5 10 mm. The calculated reduction in the thickness of the wall from the inside will be found on the basis of the law of constancy of volume and taking the internal diameter of the molded workpiece de 400 mm (Fig. 7). The dB value of 400 mm was chosen for technological reasons (reduction of tensile stresses at the beginning of the rolling process, which leads to a discontinuity of the metal; free dressing of the workpiece on the inner mill roll, etc.).

The calculated amount of reduction of the wall ceiling from the inside of the raw data substitution data is AZvn 5.5 mm.

The radius of the torus surface is determined by the proposed formula

 273 (m

„(-F1 l (-fg-) - - (55 + 5)) (() + (5.S + 5y) (SS + 5) (2 jppT) 4 (5s757 +150)

Thus, the radius of the stream on the horn of the hammer is made with a radius of 273 mm. When molded on a hammer (not shown in Fig. 7), an annular billet for rolling with an inner surface of the aperture as a part of the torus surface with a radius of 273 mm is formed.

After molding on a hammer, the billet was fed to a rolling mill where it was rolled in a closed caliber (not shown in Fig. 8) to the dimensions of the finished ring D x d xhi 600 x 520 x 150 mm.

According to the proposed method, a pilot batch (50 pcs.) Of annular products for engineering with the specified dimensions was manufactured. The pilot batch was made from blanks, the shape of the inner surface of which was determined based on the proposed dependency. Studies of the quality of the finished products have shown that there are no defects of the type of burrs in the inner diameter. At the same time investigated the quality of products manufactured by a known method (50 pcs.). Defects in these products, such as burrs of internal diameter, were observed in 80% of products, of which burrs up to 5 mm — 46%, up to 10 mm — 23%, up to 15 mm — 11%.

The average burr weight was 3 kg for each product, i.e. 150 kg for the whole batch. Therefore, it will be necessary to mechanically process 150 kg of metal (to remove the burr.

The proposed method of manufacturing ring products improves the quality of ring products by reducing defects such as burrs in internal diameter; reduces the complexity of manufacturing ring products during machining.

Claims (1)

Invention Formula A method of manufacturing ring products, in which the billet is heated, upset, pushed, pierced, molded and rolled, characterized in that, in order to improve the quality of the products obtained by eliminating the formation of a burr on the inner surface of the ring products, during the molding process ring articles are formed in the form of a torus surface, the radius of which is determined from the dependencies: Q./2+1(h/2f + (D3.) G (H / 2Y + (D8,. + L / gY (D5 „-k5 / 2) (2 l ((h / 2) 2+ (AS . "+ I / 2) J + h) where h is the height of the blank for rolling; AZVN - the calculated value of the wall thickness from the inside; d - the value of the floor of permissible limit deviations per internal diameter. Fyn Mp FIG. AT -2 te.2 5 R k "YwFig .7 0ti FW